NFC-enabled mobile phones have become increasingly popular. Also, phone sleeves or covers for such mobile phones have entered the market. These covers can be equipped with integrated sensors which are able to measure physical phenomena, such as temperature, humidity and pressure. The sensors produce measurement results that are sent from the cover to the mobile device, which is typically done via electrical connections between the cover and the mobile phone. For example, this can be done via a docking plug of the mobile phone. Subsequently, the measurement results can be processed by the mobile phone. However, creating electrical connections between the cover and the mobile phone is cumbersome and expensive.